This CSS dropdown menu, without any additional Javascript code. There are no images used and, as usual, minimal HTML markup.

HTML structure

As you can see in the following lines, the HTML structure does not contain more than we need, it’s a minimal one and easy to understand.

<ul id="menu">
        <li><a href="#">Home</a></li>
        <li>
                <a href="#">Categories</a>
                <ul>
                        <li><a href="#">CSS</a></li>
                        <li><a href="#">Graphic design</a></li>
                        <li><a href="#">Development tools</a></li>
                        <li><a href="#">Web design</a></li>
                </ul>
        </li>
        <li><a href="#">Work</a></li>
        <li><a href="#">About</a></li>
        <li><a href="#">Contact</a></li>
</ul>

The CSS

/* Main menu */
#menu
{
        width: 100%;
        margin: 0;
        padding: 10px 0 0 0;
        list-style: none;
        background: #111;
        background: -moz-linear-gradient(#444, #111);
    background: -webkit-gradient(linear,left bottom,left top,color-stop(0, #111),color-stop(1, #444));
        background: -webkit-linear-gradient(#444, #111);
        background: -o-linear-gradient(#444, #111);
        background: -ms-linear-gradient(#444, #111);
        background: linear-gradient(#444, #111);
        -moz-border-radius: 50px;
        border-radius: 50px;
        -moz-box-shadow: 0 2px 1px #9c9c9c;
        -webkit-box-shadow: 0 2px 1px #9c9c9c;
        box-shadow: 0 2px 1px #9c9c9c;
}

#menu li
{
        float: left;
        padding: 0 0 10px 0;
        position: relative;
}

#menu a
{
        float: left;
        height: 25px;
        padding: 0 25px;
        color: #999;
        text-transform: uppercase;
        font: bold 12px/25px Arial, Helvetica;
        text-decoration: none;
        text-shadow: 0 1px 0 #000;
}

#menu li:hover > a
{
        color: #fafafa;
}

*html #menu li a:hover /* IE6 */
{
        color: #fafafa;
}

#menu li:hover > ul
{
        display: block;
}

/* Sub-menu */

#menu ul
{
    list-style: none;
    margin: 0;
    padding: 0;
    display: none;
    position: absolute;
    top: 35px;
    left: 0;
    z-index: 99999;
    background: #444;
    background: -moz-linear-gradient(#444, #111);
    background: -webkit-gradient(linear,left bottom,left top,color-stop(0, #111),color-stop(1, #444));
    background: -webkit-linear-gradient(#444, #111);
    background: -o-linear-gradient(#444, #111);
    background: -ms-linear-gradient(#444, #111);
    background: linear-gradient(#444, #111);
    -moz-border-radius: 5px;
    border-radius: 5px;
}

#menu ul li
{
    float: none;
    margin: 0;
    padding: 0;
    display: block;
    -moz-box-shadow: 0 1px 0 #111111, 0 2px 0 #777777;
    -webkit-box-shadow: 0 1px 0 #111111, 0 2px 0 #777777;
    box-shadow: 0 1px 0 #111111, 0 2px 0 #777777;
}

#menu ul li:last-child
{
    -moz-box-shadow: none;
    -webkit-box-shadow: none;
    box-shadow: none;
}

#menu ul a
{
    padding: 10px;
        height: auto;
    line-height: 1;
    display: block;
    white-space: nowrap;
    float: none;
        text-transform: none;
}

*html #menu ul a /* IE6 */
{
        height: 10px;
        width: 150px;
}

*:first-child+html #menu ul a /* IE7 */
{
        height: 10px;
        width: 150px;
}

#menu ul a:hover
{
    background: #0186ba;
        background: -moz-linear-gradient(#04acec,  #0186ba);
        background: -webkit-gradient(linear, left top, left bottom, from(#04acec), to(#0186ba));
        background: -webkit-linear-gradient(#04acec,  #0186ba);
        background: -o-linear-gradient(#04acec,  #0186ba);
        background: -ms-linear-gradient(#04acec,  #0186ba);
        background: linear-gradient(#04acec,  #0186ba);
}

#menu ul li:first-child a
{
    -moz-border-radius: 5px 5px 0 0;
    border-radius: 5px 5px 0 0;
}

#menu ul li:first-child a:after
{
    content: '';
    position: absolute;
    left: 30px;
    top: -8px;
    width: 0;
    height: 0;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-bottom: 8px solid #444;
}

#menu ul li:first-child a:hover:after
{
    border-bottom-color: #04acec;
}

#menu ul li:last-child a
{
    -moz-border-radius: 0 0 5px 5px;
    border-radius: 0 0 5px 5px;
}

/* Clear floated elements */
#menu:after
{
        visibility: hidden;
        display: block;
        font-size: 0;
        content: " ";
        clear: both;
        height: 0;
}

* html #menu             { zoom: 1; } /* IE6 */
*:first-child+html #menu { zoom: 1; } /* IE7 */

CSS shape

You may have noticed the triangle shape that appears along with the sub-menu. That’s a CSS shape and its purpose is to increase usability for this menu.

It’s made using the :after pseudo-element:

#menu ul li:first-child a:after
{
    content: '';
    position: absolute;
    left: 30px;
    top: -8px;
    width: 0;
    height: 0;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-bottom: 8px solid #444;
}

#menu ul li:first-child a:hover:after
{
    border-bottom-color: #04acec;
}

Taming the IE6 “beast”

The sub-menu is displayed when hovering on a li element. As you already know, IE6 doesn’t support hovering on a non-anchor element.

Although, at the beginning of this article I said “without any Javascript”, in order maintain accessibility also for IE6, please allow me to add some scripting code:

<script type="text/javascript" src="http://code.jquery.com/jquery-latest.min.js"></script>
<script type="text/javascript">
        $(function() {
          if ($.browser.msie && $.browser.version.substr(0,1)<7)
          {
                $('li').has('ul').mouseover(function(){
                        $(this).children('ul').show();
                        }).mouseout(function(){
                        $(this).children('ul').hide();
                        })
          }
        });
</script>

You may skip that, as IE6 is going down.

The above solution requires Jquery. Also, I think this shouldn't be a problem at all, while, nowadays Jquery is almost "a default" when talking about modern websites.

Target IE6 & IE7 browsers

Besides this Jquery fallback, the above CSS includes some lines specifically for IE6 and IE7:

* html #menu             { zoom: 1; } /* IE6 */
*:first-child+html #menu { zoom: 1; } /* IE7 */

That's it.hope you like it.

The article source:http://www.red-team-design.com/css3-dropdown-menu